It is known to use a surface pipeline safety valve having a tubular member telesopically movable in the housing for controlling movement of the valve in response to pressure in the pipeline. Such a valve includes high and low pressure pilot valves for closing the safety valve.
The present invention is directed to an improved pipeline safety valve which is quick acting, in which the various seals are enclosed within the valve housing for protection, but the seals can be repaired and replaced while the valve is in the pipeline, the valve can be locked in the open position, it can be closed manually, and does not require external power for reactivation.